Extension Notes

We sometimes get in a big hurry for our fescue lawns to green up and grow. We sometimes think fertilizer is a cure-all and we need to fertilize, fertilize, and fertilize some more. Timing is important for taking care of this type of lawn. Follow a schedule that fits the type of grass — and not the homeowner.  As an example, September is the best and first month for fescue lawn fertilization, March is not. Zoysia grass, bermuda grass and buffalo grass are warm-season grasses and require a different maintenance regime. The following suggestions are for cool-season grasses such as Kentucky bluegrass or tall fescue.
March — Spot treat broadleaf weeds if necessary. Treat on a day that is 50 degrees or warmer. Rain or irrigation within 24 hours of application will reduce effectiveness.
 April — Apply crabgrass preventer when redbud trees are in full bloom (usually in April). Preventer needs to be watered in before it will start to work. Remember that a good, thick lawn is the best weed prevention and may be all that is needed.
May — Fertilize with a slow-release fertilizer if you water your lawn or if you receive enough rainfall that your turf normally doesn’t go drought-dormant during the summer. If there are broadleaf weeds, spot treat with a spray or use a fertilizer that includes a weed killer. Rain or irrigation within 24 hours of application will reduce effectiveness of the weed killer, but the fertilizer needs to be watered in. If you are using a product that has both fertilizer and weed killer, wait 24 hours after application before watering it in.
June through Mid-July — Apply second round of crabgrass preventer by June 15 - unless you have used Dimension (dithiopyr) or Barricade (prodiamine) for the April application. These two products normally provide season-long control with a single application. Remember to water it in. If grubs have been a problem in the past, apply a product containing “Merit” or “Mach 2” during the first half of July. This works to prevent grub damage. It must be watered in before it becomes active.
Late July through August — If you see grub damage, apply a grub killer that contains Dylox. Merit and Mach 2 are effective against young grubs and may not be effective on late instar grubs. The grub killer containing Dylox must be watered in within 24 hours or effectiveness drops.
September — Fertilize around Labor Day. This is the most important fertilization of the year. Water in fertilizer.
November — Fertilize. This fertilizer is taken up by the roots but is not used until the following spring. Water in fertilizer. Spray for broadleaf weeds even if they are small. Broadleaf weeds are much easier to control in the fall than in the spring. Spray on a day that is at least 50 degrees. Rain or irrigation within 24 hours reduces effectiveness. Use label rates for all products!

Scott Eckert is a Kansas State Research and Extension Agent for Harvey County, specializing in horticulture.